Pressure control devices



y 1959 e. E SWANSON 2,897,310

PRESSURE CONTROL DEVICES Filed Aug. 8, 195'! 2 Sheets-Sheet 1 FIG. 2

INVENTOR GODFREY E. SWANSON AT TORNEYS July 28,1959 3, sw soN 2,897,310

PRESSURE CONTROL DEVICES Filed Aug. 8, 1957 2 Sheets-Sheet 2 FIGQS l9 l8 I i f 49 P M 56 I8 39 i m. I I I v, 27 I5 ul,

. 2 6 I l I8 28 FIG. 7

l6 INVENTOR l4 25 GODFREY E. SWANSON ATTORNEYS United States Patent PRESSURE CONTROL DEVICES Godfrey E. Swanson, Hopkins, Minn.

Application August 8, 1957, Serial No. 677,008

10 Claims. (Cl. 200-83) The herein disclosed invention relates to pressure control devices and particularly to a device for operating an electric switch.

An object of the invention is to provide a device of such character which will be exceedingly sensitive in operation and which can be used to control the operation of a burner upon variations in the draft of the burner.

Another object of the invention resides in providing a case having two sections with marginal portions overlying one another and' a diaphragm of thin flexible material having its edges clamped between the marginal portions of said sections and forming with one of these sections a compartment with which the pressure controlling fluid comrnunicates.

A still further object of the invention resides in attaching to the diaphragm inwardly of the edges thereof a rigid plate and in further providing strap hinges constructed of thin flexible material with relatively high tensile strength, said strap hinges being secured to said plate and to one of the sections of said case at the marginal portion thereof.

An object of the invention resides in providing a spring connected to said plate at a locality opposite said hinges and to said case and pulling said plate in the direction of the length of said hinges.

A feature of the invention resides in attaching a post to said plate extending outwardly through one of said sections and in further providing an electric switch mounted on said section and operated by said post upon movement of the plate.

Other objects of the invention reside in the novel combination and arrangement of parts and in the details of construction hereinafter illustrated and/or described.

In the drawings:

Fig. 1 is an elevational View of a pressure control device illustrating an embodiment of the invention.

Fig. 2 is a side elevational view of the construction shown in Fig. 1.

Fig. 3 is a sectional detail view of a portion of the structure shown in Fig. l drawn to a greater scale and taken on line 33 of Fig. 1.

Fig. 4 is a sectional detail view taken on line 4-4 of Fig. 1 and drawn to a greater scale.

Figs. 5 and 6 are views similar to Figs. 1 and 2 of a modification of the invention.

Fig. 7 is an elevational-sectional view of a portion of the structure shown in Fig. 5 and taken on line 77 of Fig. 5 and drawn to a greater scale.

The form of the invention shown in Fig. 1 consists of a case 10 constructed of sheet metal in two sections 11 and 12. In the form of the invention shown the sections 11 and 12 are similar and are provided with body portions 13 and 14 and with marginal portions 15 and 16 projecting outwardly therefrom. The marginal portions 15 and 16 are planiform and overlie one another. Disposed between said marginal portions is a diaphragm 17 constructed of a thin, flexible and elastic Patented July 28, 1959 material such as rubber or the like. This diaphragm is clamped in position between the marginal portions 15 and 16 by means of bolts 18 and 19 which extend jointly through said marginal portions and diaphragm.

Attached to the diaphragm 17 and on each side thereof are metal plates 21 and 22. These plates are secured to said diaphragm by means of bolts 23 and 24 which extend through said plates and diaphragm. The said plates and diaphragm form a movable unit 25 which is suspended for swinging movement by means of two strap hinges 124. These hinges are constructed of thin flexible material such as Phosphor bronze or the like and the upper ends of the same are clamped in position between the marginal portion 15 of the case section 11 and the diaphragm 17. The bolts 19, previously referred to, extend through these hinges and hold the same attached to the case 10. In a similar manner the lower ends of the hinges 124 are clamped between the diaphragm 17 and the plate 21. Likewise, the bolts 23, previously referred to, extend through the lower ends of said hinges and hold the same securely attached to the plates 21 and 22. By means of this construction, the unit 25 is suspended for swinging movement on the hinges 124, the weight of the said unit being borne by said hinges and the upper marginal portions of the diaphragm 17 being relieved of the stress produced in supporting the unit.

At the lower portion of the unit 25 is provided a tension coil spring 26. The upper end of this coil spring is hooked in a hole 27 in the lowermost portion of the plate 21 while the lower end of said spring is hooked over a bolt 28 which passes through the marginal portions 15 and 16 of the sections 11 and 12 of case 10 and the diaphragm 17. This spring is initially tensioned so that the same pulls in the direction of the plane of the plates 21 and 22 and maintains the unit 25 in an intermediate normal position between the sections 11 and 12 of the case and substantially planiform with respect to the marginal portions 15 and 16 of the sections of the case.

The diaphragm 17 forms a tight connection with the marginal portions 16 of section 14 and thus provides a chamber 29 within said case and on one side thereof. A suitable fitting 31 with tube connections 32 is attached to the body 14 of section 12 and communicates with the chamber 29. This fitting may be connected through a tube 33 with any source of fluid, the variations in pressure of which are utilized to operate the device.

In the form of the invention shown in Fig. 1, a switch 34 is shown which is desired to be operated by the device. This switch may be of ordinary construction and preferably one in which an operating button 35 is employed and which is adapted to be moved an exceedingly short distance to operate the switch proper. Connectors 36 provided with the switch serve to connect the same to the circuit in which the switch is used. The switch 34 is attached to a bracket 37 by means of screws 38 and is disposed with the button 35 facing the body portion 13 of section 11.

The switch 34 is operated by means of a post 39 which is in the form of a bolt having a threaded shank 41 and a head 42. This post passes through the unit 25 and is clamped in position thereon by means of a nut 43. The post 39 passes through an opening 54 in the body portion 13 of section 11. The shank 41 has screwed on it two other nuts 44 and 45 which clamp therebetween an arm 40 adapted to engage the button 35. The upper end of the post 39 is biased for movement in an upward direction by means of a tension coil spring 4-6. One end 47 of this coil spring is hooked over the upper end of the post 39 while the other end is screwed on a nut 4-8. An adjusting screw 49 passes through a bracket 51 secured to the body portion 13 of section 11 and is screwed into the nut 48. By means of this construction the tension on the post 39 can be adjusted at will. The switch 34 and operating mechanism therefor is contained within a box 52 secured to the body portion 13 and has a cover 53 detachably mounted thereon and by means of which access to said switch may be had.

In Figs. 5, 6 and 7 a modification of invention has been shown in which a different type of switch is employed. The control device proper is the same as that shown in Figs. 1 to 4 and the same reference will be used to designate the corresponding parts.

In the form of the invention shown in Figs. 5, 6 and 7, the post 39 is not utilized for operating the switch but has the spring 46 connected to the same and serves to bias the unit 25 in the proper direction. in addition, a similar post 55 is employed which is attached to the plates 21 and 22 near the lower edges of the same. This post projects through an opening 56 in the body portion 13 of section 11. The post 55 is secured to said unit by means of a nut 57 and has two nuts 58 and 59 screwed on the same. Between these nuts is clamped an arm 61 which has attached to it a flexible contact finger 62. This contact finger has secured to the end of it movable contacts 63 and 64 which are adapted to alternately engage either of two fixed contacts 65 and 66. The contacts 65 and 66 are screwed into posts 67 and 68 which are mounted on an insulating bar 71. This bar is attached by means of screws 72 to a bracket 73 which in turn is attached to the body portion 13 of section 11. This construction forms a switch indicated in its entirety by the reference numeral 70. The switch 70 has not been illustrated as mounted within a box though it can readily be comprehended that such construction may be provided if desired.

The manner of using the invention is obvious. The bias to the movement of the diaphragm is controlled through the adjusting screw 49 which varies the spring tension of the spring 46 on the post 39. The arm n? is adjusted so that when the desired variation in pressure in chamber 29 occurs, that the button 35 is moved from opening to closing position and vice versa. This is accomplished by means of adjustment of the screws 44 and 45. In the form of the invention shown in Figs. 5, 6 and 7, similar adjustments are made by means of the screws 55 and 56 and the nuts 58 and 59. The device illustrated has been designed for use in responding to draft or suction and spring 46 is so arranged. If desired, the device can be made to respond to pressure by arranging the spring 46 as shown in dotted lines at 50 in Fig. 1.

The advantages of the invention are manifest. The device is exceedingly sensitive and is readily subject to slight variations in draft or pressure. By means of the construction shown, heating plants may be automatically controlled upon variations in the draft of the furnace. The device can be constructed at a nominal expense and by tools and equipment readily available for the purpose.

Changes in the specific form of the invention, as herein described, may be made within the scope of What is claimed without departing from the spirit of the invention.

Having described the invention, what is claimed as new and desired to be protected by Letters Patent is:

1. A pressure controlled device comprising a case having two sections with marginal portions overlying one another, a diaphragm of thin flexible material having its edges clamped between the marginal portions of said sections and forming with one of the sections a chamber, a rigid plate attached to said diaphragm with its edges disposed inwardly of the clamped edges, said diaphragm and plate forming a movable unit, strap hinges constructed of thin flexible material with relatively high tensile strength secured to said unit at the locality of one of the edges of said plate and to said case at the marginal portion of one of the sections thereof, means acting between said plate and case and maintaining said strap hinges taut,

means :for conducting the pressure controlling fluid to said chamber and motion transmitting means connected to said plate.

2. A pressure controlled device comprising a case having two sections with marginal portions overlying one another, a diaphragm of thin flexible material having its edges clamped between the marginal portions of said sections and forming with one of the sections a chamber, a rigid plate attached to said diaphragm with its edges disposed inwardly of the clamped edges, said diaphragm and plate forming a movable unit, strap hinges constructed of thin flexible material secured to said unit at the locality of one of the edges of said plate and to said case at the marginal portion of one of the sections thereof and a spring connected to said plate at a locality opposite said hinges and to said case and pulling said plate in the direction of the length of said hinges to maintain said hinges taut and resisting movement of said unit, means for conducting the pressure controlling fluid to said chamber and motion transmitting means connected to said plate.

3. A pressure controlled device comprising a case having two sections with marginal portions overlying one another, a diaphragm of thin flexible material having its edges clamped between the marginal portions of said sections and forming with one of the sections a chamber, a rigid plate attached to said diaphragm with its edges disposed inwardly of the clamped edges, said diaphragm and plate forming a movable unit, strap hinges constructed of thin flexible material secured to said unit at the locality of one of the edges of said plate and to said case at the marginal portion of one of the sections thereof, and a tension coil spring connected to said plate at a locality opposite said hinges and to said case and pulling said plate in the direction of the length of said hinges to maintain said hinges taut and resisting movement of said unit, means for conducting the pressure controlling fluid to said chamber and motion transmitting means connected to said plate.

4. A pressure controlled device comprising a case hav ing two sections with marginal portions overlying one another, a diaphragm of thin flexible material having its edges clamped between the marginal portions of said sections and forming with one of the sections a chamber, a rigid plate attached to said diaphragm with its edges disposed inwardly of the clamped edges, strap hinges constructed of flexible metal and connected to said plate at one edge thereof and to said case, means acting between said plate and case and maintaining said strap hinges taut, means for conducting the pressure controlling fluid to said chamber and motion transmitting means connected to said plate.

5. A pressure controlled device comprising a case having two sections with planiform marginal portions overlying one another and disposed in a substantially vertical position, a diaphragm of thin flexible material having its edges clamped between the marginal portions of said sections and forming with one of the sections a chamber, a rigid plate attached to said diaphragm with its edges disposed inwardly of the clamped edges, said diaphragm and plate forming a movable unit, strap hinges constructed of thin flexible material secured to said unit at the locality of the upper edge of said plate and to said case at the upper marginal portion of one of said sections, a tension coil spring connected to said plate at the lower edge thereof and to said case at the locality of the lower marginal portion of one of said sections to maintain said hinges taut and resisting movement of said unit, means for conducting the pressure controlling fluid to said chamber and motion transmitting means connected to said plate.

6. A pressure controlled device comprising a case having two sections with marginal portions overlying one another, a diaphragm of thin flexible material having its edges clamped between the marginal portions of said sections and forming with one of the sections a chamber, a rig F Plate attached to said diaphragm with its edges disposed inwardly of the clamped edges, said diaphragm and plate forming a movable unit, strap hinges constructed of thin flexible material secured to said unit at the locality of one of the edges of said plate and to said case at the marginal portion of one of the sections thereof, and a tension coil spring connected to said plate at a locality opposite said hinges and to said case and pulling said plate in the direction of the length of said hinges, means for conducting the pressure controlling fluid to said chamber, a switch having a movable member and means fixedly connected to said plate and directly engaging said movable member to actuate said switch.

7. In a pressure controlled device comprising a case having two sections with marginal portions overlying one another, a diaphragm of thin flexible material having its edges clamped between the marginal portions of said sections and forming with one of the sections a chamber, a rigid plate attached to said diaphragm with its edges disposed inwardly of the clamped edges, said diaphragm and plate forming a movable unit, means for conducting the pressure controlling fluid to said chamber, motion transmitting means connected to said plate, the combination of strap hinges constructed of thin flexible material with relatively high tensile strength secured to said unit at the locality of one of the edges of said plate and to said case at the marginal portions of one of the sections thereof, and tensioning means acting between said unit and said case at a locality opposite said strap hinges and maintaining said strap hinges taut.

8. In a pressure controlled device comprising a case having two sections with marginal portions overlying one another, a diaphragm of thin flexible material having its edges clamped between the marginal portions of said sections and forming with one of the sections a chamber, a rigid plate attached to said diaphragm with its edges disposed inwardly of the clamped edges, said diaphragm and plate forming a movable unit, means for conducting the pressure controlling fluid to said chamber, motion transmitting means connected to said plate, the combination of strap hinges constructed of thin flexible material with relatively high tensile strength secured to said unit at the locality of one of the edges of said plate and to said case at the marginal portions of one of the sections thereof, and a tension coil spring connected to said plate at a locality opposite said hinges and to said case and pulling said plate in the direction of the length of said hinges to maintain said hinges taut.

9. In a pressure controlled device comprising a case having two sections with marginal portions overlying one another, a diaphragm of thin flexible material having its edges clamped between the marginal portions of said sections and forming with one of the sections a chamber, a rigid plate attached to said diaphragm with its edges disposed inwardly of the clamped edges, said diaphragm and plate forming a movable unit, means for conducting the pressure controlling fluid to said chamber, motion transmitting means connected to said plate, the combination of strap hinges constructed of thin flexible metal secured to said unit at the locality of one of the edges of said plate and to said case at the marginal portion of one of the sections thereof, and a tension coil spring connected to said plate at the edge thereof opposite said strap hinges and to said case at a locality opposite said strap hinges and acting in the direction of the length of said hinges to maintain said strap hinges taut.

10. In a pressure controlled device comprising a case having two sections with marginal portions overlying one another and disposed in a substantially vertical plane, a diaphragm of thin flexible material having its edges clamped between the marginal portions of said sections and forming with one of the sections a chamber, a rigid plate attached to said diaphragm with its edges disposed inwardly of the clamped edges, said diaphragm and plate forming a movable unit, means for conducting the pressure controlling fluid to said chamber, motion transmitting means connected to said plate, the combination of strap hinges constructed of thin flexible metal secured to said unit at the locality of one of the edges of said plate and to said case at the marginal portion of one of the sections thereof, and a tension coil spring connected to said plate at the edge thereof opposite said strap hinges and to said case at a locality opposite said strap hinges and acting in the direction of the length of said hinges to maintain said strap hinges taut.

References Cited in the file of this patent UNITED STATES PATENTS 1,466,242 Neal Aug. 28, 1923 1,466,243 Neal Aug. 28, 1923 1,952,107 Wilson Mar. 27, 1934 2,480,847 Geisel Sept. 6, 1949 2,547,050 Simmons Apr. 3, 1951 2,794,088 Ostby May 28, 1957 2,824,920 Humphreys Feb. 25, 1958 

